I am in my first year and my first course unit is Epidemiology, I am benefiting from this lecture, I am still grasping the whole concept. Thank you so much
@nurhafizsahzaimey8433
9 жыл бұрын
hi! I just wanna thank you for this video. I just finished my epidemiology paper today and I couldn't do it if its not because of you. thank you so much for your videos. you're the real MVP. =)
@FRACP
8 жыл бұрын
This is excellent! Other videos I found simply went through the 'cross-method' without explaining the proper way first (which I figured out myself) but I'm glad you're video confirmed it!
@shinom0ri
3 жыл бұрын
Pobably the best video to illustrate OR I've seen. For visualisation purposes I think showing why OR approaches RR with an example might be a good idea, since it's not hard to demonstrate, but seems like a neubulous statement often mentioned otherwise...
@phanicemaroria9177
Жыл бұрын
well elaborated hv been given an assignment have used all your example to work it out thanks alot
@evabudinska692
10 жыл бұрын
Hi Elizabeth, thanks for this video. I was wondering which of the two types of interpretations of OR is most common. The second one is to calculate OR as (a/b) / (c/d) which gives the same result: (a*d)/(c*b), however, it is interpreted as odds ratio between odds of event in the exposed group vs odds of event in the non-exposed group.
@musaabass5731
8 ай бұрын
Well explained. Thanks 👍
@Daniel-rk2qz
8 жыл бұрын
+Elizabeth Lynch So... can we say that we only use case-controls when a disease (outcome) is rare and so we want to find the risk factors? Whereas otherwise, if the disease is prevalent, then it is a BETTER option to use a cohort study? And does this also mean that our ULTIMATE GOAL is to find a good estimation for a relative risk in order to determine how it affects the person's pre-test probability? Thank you! this is probably the most challenging part of med school haha.
@aishasultan8003
Жыл бұрын
Thank you so much, such a helpful and simple video.
@zeedee6688
6 жыл бұрын
great explanation. Thanks
@RamirezHD
10 жыл бұрын
I was looking on how to interpret the null hypothesis for the odds ratio...but nice video.
@ElizabethLynch
10 жыл бұрын
Not sure what you mean. The null hypothesis would be an OR of 1.0, meaning there was an equal likelihood of seeing the exposure in cases and controls.
@CraigDeLarge
4 жыл бұрын
+elizabeth, Thanks for these. You are becoming my salvation in a course I am taking now. What markup device and software are you using in this video? I want to adopt it for work I am doing. Thanks for reply.
@Wald4267
11 ай бұрын
Because the outcome is rare does that mean 1.11 is a big increase in risk
@haarisarain5048
3 жыл бұрын
watching this in 2020 feels very relevant.
@spencerwilliams3385
6 жыл бұрын
Why do we cross multiple? Thanks for the video.
@maxamedcabdulilaah3299
Жыл бұрын
Thank u teacher
@geosui3522
10 жыл бұрын
Very helpful video..I have a question though, even though it has not been mentioned in this video: how we calculate the logarithm of Odds Ratio? for example, if the odds ratio is 0.71, how do we calculate InOR?
@somebody6492
2 жыл бұрын
Hello do you have a vid on how to calculate unmatched ratio? Ty.
@DPREY1234
2 жыл бұрын
So, is it correct to say that "I can use OR in cohort studies only when the prevalence is very low (rare disease)" ?????
@kenthhuncho6887
11 ай бұрын
U helped me coz i dodged this lecture
@Neunhoffer
2 жыл бұрын
Hi. I am trying to figure out how the cdc arrived at 2.34 times odds for their covid study in kentucky. I cant figure out how this is calculated. Can you help?
@peenleib
9 жыл бұрын
Still don't understand why you can't use RR in case-control studies (in fact you have all numbers needed to calculate it). Could you explain it for me once again?
@ProfFeinman
3 жыл бұрын
Risk = probability = wins / total events. Odds = wins / losses = wins / (total events - wins). For example: Risk of drawing an ace from fair deck = 4/52 = 1/13 = 0.077 Odds = 4/48 =1/12 = 0.083. If the comparison group also has low incidence, the ratios will also be similar. So, as she says on the video, if even is rare, odds and risk are similar and RR and OR may be the same.
@mohammed.f7773
4 жыл бұрын
thank you so much
@jinikaty1908
3 жыл бұрын
Thanks
@crystal5263
10 жыл бұрын
How can you tell the disease is rare or not rare if all that is given is the Odds Ratio is 5 (p > .001)?
@ElizabethLynch
10 жыл бұрын
This is not something you can determine from the OR. you need information about the prevalence of the disease.
@crystal5263
10 жыл бұрын
Elizabeth Lynch We were not given the prevalence of the disease the question is " Case control study reviewing relationship between Tampon use and Toxic shock syndrome (TSS). OR comparing the two was 5.0 (p < 0.001). They conclude risk of TSS is 5 times higher in tampon users. Conclusion is valid if which following assumption is satisfied? Then the answer was TSS is a rare disease thus a low prevalence... So what I was wanting to know is how did they come to conclude it had a lower prevalence from that question stem?
@ElizabethLynch
10 жыл бұрын
Crystal Hinojosa Because the OR should only be used to estimate relative risk when the outcome is rare, and they are using the OR to estimate relative risk.
@crystal5263
10 жыл бұрын
I'm not understanding what you mean by the outcome is rare? How do I know it is a rare disease is there a certain target number? Since it was only 5 times higher does that mean rare?
@RahulKumar-jk6oi
10 жыл бұрын
Crystal Hinojosa Can you please provide the reference you looked for the outcome? However, it is good approximation of the equivalence between odd ratio to relative risk ratio when prevalence of disease is
Пікірлер: 35